Is there a theoretical upload and download min/max for a Linode?

Could you say: each physical host has a bandwith of x/kbits upstream and y/kbits downstream. Each physical machine hosts a max of z Linodes => The guaranteed up/down rates are x/z and y/z kbits with a possibility to go as high as x and y kbits if all other Linodes disconnect.

Just wondering because I'm going to experiment with traffic shaping to speed up ssh and other important traffic to my Linode and configurations often need a bandwith parameters.

Yes, I wouldn't mind this either. I realise the results would be horribly inaccurate, but oh wells.

I seem to recall someone from Linode once mentioned in IRC that they've got a 100 Mbit connection; so the most any single Linode could get is 100 Mbit/sec at the very most. Usually less, but still pretty darned quick!

Don't think there's any minimum other than 0 Kbit/sec.